/* Test file for mpfr_ui_div.

Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the MPFR Library.

The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the MPFR Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301, USA. */

#include <stdio.h>
#include <stdlib.h>

#include "mpfr-test.h"

/* checks that y/x gives the right result with 53 bits of precision */
static void
check (unsigned long y, const char *xs, mp_rnd_t rnd_mode, const char *zs)
{
  mpfr_t xx, zz;

  mpfr_inits2 (53, xx, zz, (void *) 0);
  mpfr_set_str1 (xx, xs);
  mpfr_ui_div (zz, y, xx, rnd_mode);
  if (mpfr_cmp_str1(zz, zs))
    {
      printf ("expected quotient is %s, got ", zs);
      mpfr_out_str (stdout, 10, 0, zz, GMP_RNDN);
      printf ("mpfr_ui_div failed for y=%lu x=%s with rnd_mode=%s\n",
              y, xs, mpfr_print_rnd_mode (rnd_mode));
      exit (1);
    }
  mpfr_clears (xx, zz, (void *) 0);
}

static void
check_inexact (void)
{
  mpfr_t x, y, z;
  mp_prec_t px, py;
  int inexact, cmp;
  unsigned long int u;
  int rnd;

  mpfr_init (x);
  mpfr_init (y);
  mpfr_init (z);

  for (px=2; px<300; px++)
    {
      mpfr_set_prec (x, px);
      do
        {
          mpfr_random (x);
        }
      while (mpfr_cmp_ui (x, 0) == 0);
      u = randlimb ();
      for (py=2; py<300; py++)
        {
          mpfr_set_prec (y, py);
          mpfr_set_prec (z, py + px);
          for (rnd = 0; rnd < GMP_RND_MAX; rnd++)
            {
              inexact = mpfr_ui_div (y, u, x, (mp_rnd_t) rnd);
              if (mpfr_mul (z, y, x, (mp_rnd_t) rnd))
                {
                  printf ("z <- y * x should be exact\n");
                  exit (1);
                }
              cmp = mpfr_cmp_ui (z, u);
              if (((inexact == 0) && (cmp != 0)) ||
                  ((inexact > 0) && (cmp <= 0)) ||
                  ((inexact < 0) && (cmp >= 0)))
                {
                  printf ("Wrong inexact flag for u=%lu, rnd=%s\n",
                          u, mpfr_print_rnd_mode ((mp_rnd_t) rnd));
                  printf ("expected %d, got %d\n", cmp, inexact);
                  printf ("x="); mpfr_print_binary (x); puts ("");
                  printf ("y="); mpfr_print_binary (y); puts ("");
                  printf ("y*x="); mpfr_print_binary (z); puts ("");
                  exit (1);
                }
            }
        }
    }

  mpfr_clear (x);
  mpfr_clear (y);
  mpfr_clear (z);
}

static void
check_nan (void)
{
  mpfr_t  d, q;

  mpfr_init2 (d, 100L);
  mpfr_init2 (q, 100L);

  /* 1/+inf == 0 */
  MPFR_CLEAR_FLAGS (d);
  MPFR_SET_INF (d);
  MPFR_SET_POS (d);
  MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_number_p (q));
  MPFR_ASSERTN (mpfr_sgn (q) == 0);

  /* 1/-inf == -0 */
  MPFR_CLEAR_FLAGS (d);
  MPFR_SET_INF (d);
  MPFR_SET_NEG (d);
  MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_number_p (q));
  MPFR_ASSERTN (mpfr_sgn (q) == 0);

  /* 1/nan == nan */
  MPFR_SET_NAN (d);
  MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_nan_p (q));

  /* 0/0 == nan */
  mpfr_set_ui (d, 0L, GMP_RNDN);
  MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_nan_p (q));

  /* 1/+0 = +inf */
  mpfr_set_ui (d, 0L, GMP_RNDN);
  MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_inf_p (q) && mpfr_sgn (q) > 0);

  /* 1/-0 = -inf */
  mpfr_set_ui (d, 0L, GMP_RNDN);
  mpfr_neg (d, d, GMP_RNDN);
  MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_inf_p (q) && mpfr_sgn (q) < 0);

  /* 0/1 = +0 */
  mpfr_set_ui (d, 1L, GMP_RNDN);
  MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_cmp_ui (q, 0) == 0 && MPFR_IS_POS (q));

  /* 0/-1 = -0 */
  mpfr_set_si (d, -1, GMP_RNDN);
  MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, GMP_RNDZ) == 0); /* exact */
  MPFR_ASSERTN (mpfr_cmp_ui (q, 0) == 0 && MPFR_IS_NEG (q));

  mpfr_clear (d);
  mpfr_clear (q);
}

static int
mpfr_inv (mpfr_t y, mpfr_t x, mp_rnd_t r)
{
  return mpfr_ui_div (y, 1, x, r);
}

int
main (int argc, char *argv[])
{
  tests_start_mpfr ();

  check_nan ();
  check_inexact ();
  check(948002822, "1.22191250737771397120e+20", GMP_RNDN,
        "7.758352715731357946e-12");
  check(1976245324, "1.25296395864546893357e+232", GMP_RNDZ,
        "1.5772563211925444801e-223");
  check(740454110, "2.11496253355831863313e+183", GMP_RNDZ,
        "3.5010270784996976041e-175");
  check(1690540942, "1.28278599852446657468e-276", GMP_RNDU,
        "1.3178666932321966062e285");
  check(1476599377, "-2.14191393656148625995e+305", GMP_RNDD,
        "-6.8938315017943889615e-297");

  /* inv is for 1/x */
  data_check ("data/inv", mpfr_inv, "mpfr_ui_div(1,x)");

  tests_end_mpfr ();
  return 0;
}
